[Intraerythrocytic potassium and diuretic therapy].

Diuretic-induced hypokalemia is one of the most common and important disturbances during antihypertensive therapy. However, it has been suggested that determination of serum potassium levels may not reflect significant changes of its intracellular concentration. This study was performed to evaluate whether there is any change of red cell potassium concentration as compared to serum potassium levels, in ten patients receiving chlorthalidone, 25 mg/day, during 4 weeks. Significant antihypertensive effect was achieved and despite serum potassium levels less than 3.5 mEq/1 occurred in four patients, no significant change in intracellular concentration of potassium was observed in this population with essential hypertension.